Collar protector



' c. E. RICKARD COLLAR PROTECTOR July 7, 1959 Filed Nov. 19, 1957 2w i h 7 g G 6 0 E 3 2 E United States Patent COLLAR PROTECTOR Clyde E. Rickard, Pittsburgh, Pa., assignor to McDowell Manufacturing Company, Millvale, Pa., a corporation of Pennsylvania This invention pertains to thread protectors and particularly to those of a collar or cap type.

Thread protectors are employed in connection with the threaded end portions of pipe, casing and conduit members during shipping and handling. The purpose is to prevent distortion of the end portions and particularly, of their threads, so that they may be used as needed to provide a good and fluid-tight joint.

It has been an object of my invention to devise a new and improved type of thread protector for threaded end portions of pipe, casing or conduit members and particularly, for externally-threaded or pin members;

Another object of my invention has been to provide a collar or cap type of protective housing body for the threaded end portions of easing members that may be quickly and easily assembled and disassembled with a minimum of effort, and while assuring an aligned relation during the mounting operation;

A further object has been to device an external thread protector collar, cap, part or device which will have a front guide portion and back mounting or securing portion wherein, the guide portion has a radially-offset relationship with respect to the mounting portion and with respect to the end portion of the member on which it is to be mounted;

A still further object has been to devise a protector collar construction that employs threaded sectors, segments or areas of different diameter for guiding and mounting purposes, which areas have an axially or longitudinallyspaced or segregated relationship with each other;

These and other objects of the'invention will appear from the description and the drawings of the illustrated embodiment thereof.

In the drawings,

Figure 1 is a top plan view of a thread protector made in accordance with my invention, and in an assembled position with the pin or end portion of a threaded casing that is to be protected;

Figure 2 is an enlarged vertical sectional fragment through the assembly of Figure l, but showing the protector in a preliminarily inserted or initial position with respect to the threaded conduit;

Figure 3 is a view similar to and on the same scale as Figure 2, and showing the protector in a fully mounted, secured or assembled relationship with respect to the conduit; this figure is taken along the line HI-III of Figure 1.

Referring to the drawings, 1 have illustrated a pipe, conduit or casing member whose longitudinal end portion 11 is provided with external or male threads therealong. As noted in Figures 2 and 3, the threads may be provided with a slight taper along the length of the pipe, as is customary in the fluid conduit industry. To protect such end portion of the member 10, I have shown a thread protector cap, collar, part or device 14 of a somewhat cylindrical shape. The protector 14 is adapted to, as shown in Figure 2, be first slid longitudinally or axially forwardly to a preliminary position, such that its mount- 2,893,438 Fatented July 7, 1959 out sweep shaped back end wall portion 15 that serves as a protector shoulder and rim flange for the corner and end wall of the casing member 10. As emphasized particularly in Figure 3, the cross or transverse extent of the flange wall portion 15 is such that it projects radially-inwardly beyond the full wall thickness or depth of the member 10 to give the latter maximum protection against end thrust, etc. Preferably, as shown in Figure 3, the final mounting position is such that the back wall flange portion 15 serves as a limit stop, but has a slight clearance or spacing with respect to the conduit member to provide a resilient or flexible type of protection. The housing body of the protector 14 is of a suitable resilientlyflexible material such as steel. It will be noted that the flange 15 is convexly bent or curved outwardly about end threads of the portion 11 to provide them with a spaced type of resilient bumper, and to also minimize the required intermeshing or thread turns to accomplish a secure mounting of the protector on the end portion of the casing.

A back end wall area or cylindrical portion 17 has internal threads whose diameter is such as to provide a cloself intermeshing or interfitting relationship with the threads 11 of the conduit. However, it will be noted that the contact between the threads is along a pitch line or cone that lies along sloped flanks of the cooperating threads, and that a spaced or clearance relationship is maintained by cooperating crest and root portions of the threads.

The back wall flange 15, in effect, extends with an outward sweep to integrally connect with the mounting, threaded, back wall portion 17. As shown particularly in Figure 2, the back wall portion 17 is connected to a threaded front and axially spaced-apart guide wall portion 21 by a hand-grip, intermediate cylindrical band or wall portion 19. The intermediate wall portion 19 is shown radially-outwardly offset both with respect to the threaded wall portions 17 and 21 and with respect to the threads of the casing end portion 11.

Outwardly sloped shoulders 18 and 20 serve to integrally connect the Wall portions 17 and 21 to the intermediate portion 19. A third, outwardly-inclined shoulder wall portion 22 serves to integrally connect the guide wall portion 21 with a front protector skirt or nose wall portion 23. The skirt wall portion 23 is also shown of cylindrical or band shape and as always having a radiallyoutwardly-spaced relationship with the threaded end portion 11 of the casing member 10 (compare Figures 2 and 3).

When the protector 14 of my construction is to be mounted on a casing member 10 and its front end has been moved towards the front end 11 of the member, the front skirt or nose portion 23 first enters over and about the threaded portion 11 to give a rough, preliminary onguided relationship. Then, when the threads of the front guide wall portion 21 move into alignment at their forward end with the threaded end portion 11, they will, in effect, slide forwardly thereover with a minimum clearance spacing to the position indicated in Figure 2. At this time, as previously intimated, the protector 14 is turned to its secured relation by the close intermeshing engagement of the threads of the back wall or mounting portion 17 with respect to corresponding threads of the end portion 11. Such turning-on action may be facilitated by employing the bands 19 and 23 and the wall flange as manual or tool gripping portions, depending upon the size of the members involved.

The mounted protective relationship of the device 14 is such that it has a series of spaced-apart, resiliently-flexible, offset wall portions that serve as bumpers and which have no direct contact with the end portion of the conduit member when such member is in its normal mounted relationship as to the device. In Figure 3, I have shown a spatial difference between the pitch line of the threads of the casing member 10 and the pitch line of the offset threads of front wall portion 21. Preferably, this spatial difference should be about .025 of an inch on a side, which gives a difference of about .050 of an inch on thediameter. This not only provides clearance for the front threads, but permits the back threads of the protector to quickly contact the ends of the threads of the conduit member 10.

The flank contact between threads of the protector 14 and the casing member iii assures a minimum number of threads to accomplish the securing ormounting operation, while at the same time, minimizes the effort in mounting and dismounting the protector. It also protects the crests and the roots of the threaded end 11 of the casing member and allows the front or guide wall portion 21 to enter and leave a loose intermeshing or cooperating relationship with the threads of the conduit member as it advances on the taper, without damage, to the conduit member (see Figure 3). As shown in Figure 3, the slight taper of the threaded portion It of the casing member and particularly, with respect to the radially inwardly offset threaded portion 21 causes the front or guide wall portion 21 to contact the threaded portion 11 as it is advanced on the taper, and provides the loose intermeshing or cooperating relationship with the threads of the casing member that is shown in Figure 3.

It will be noted that the pitch cone of the threads of the back or mounting portion 17 is tightened on the pitch cone of the threads of the end portion 11. Employing my construction, if there is any slight cocking during mounting of the device 14, it may be rotated until the thread pitch is located.

As shown in Figures 2 and 3, the threaded or pin end portion 11 of the casing 16 will ordinarily have a slight taper along its threads. The purpose, of course, is to provide a tightening-down, clamping type of joint when the casing is used. The cup-like protector cap 14 of my invention is also shown provided with a slight taper along the inside threads of its front wall portion 21 and its back wall portion 17. As shown in Figure 3, this tapering is of aid in providing a tight clamping relationship between the protector cap 14 and the casing 10 as the tightening-down operation progresses. A stand-off of about /s of an inch will provide a suitable tighteningdown on the diameter of the threads.

What I claim is:

1. A collar protector for a tapered externally-threaded end portion of a casing member which comprises, a substantially hollow housing body having a front guide wall portion and a back mounting wall portion, said back wall portion having internal threads to solely engage the threads of the end portion of the casing member on and immediately adjacent to a common pitch cone therealong, said front wall portion having a forwardly and radiallyoffset relation with respect to said back wall portion, internal threads formed in said front wall portion having a pitch cone offset from a pitch cone of said casing member to provide an initial slide-clearance relationship with respect to the threads of the end portion, so as to slide forwardly over the member until the threads of said back wall portion engage the threads of the end portion and to then form a loose cooperating relationship with the threads of the end portion as the protector is advanced on the taper, and said body having an intermediate con necting outwardly-oflset wall portion positioned to provide-a gripfor rotating said body relative to the member.

2. A protector as defined in claim 1 wherein the pitch cone engagement is only between the flanks of the threads of said back portion and the flanks of the threads of the end portion of the casing member.

3. A protector as defined in: claim 1 wherein, said housing body is of resilient wall construction, the threads of said front wall portion are moved into a loose intermeshing relationship. with the, threads of the end portion of the casing memberwhen said body is securely mounted on the threaded end portion, and threads of said back wall portion have an interfitting relation with respect to the threads of the end portion when said back wall portion is securely mounted onthe end, portion, and said front and back wall portions are slightly tapered to respectively provide the loose intermeshing relationship of said front wall portion and the interfitting relation of said back wall portion.

4. A collar protector for a threaded pin end portion of a casing member which comprises, a hollow housing body having a front guide wall portion and a back mounting wall portion, said front and back mounting wall portions being internally-threaded therealong, said front wall portion having a radially-outwardly-offset relationship with respect to said back wall portion, so that the threads on said front wall are radially-offset with respect to the threads on said back wall portion to provide an initial slide-on advance of said, housing body over the pin end portion of the member and a close meshing engagement of the threads of said back wall portion over the threads of the pin end portion, said back wall threads engaging the threads of said member solely along their respective flanks, so that there is a spatial relation between the respective roots and crests of the threads, said front wall threads being positioned, in an opposed guiding and cooperating alignment with the threads of said casing member when the protector is in an assembled position, a backwardly-swept flange wall portion projecting from said back wall portion and across the end wall thickness of the pin end of the member in a spaced relationship with respect to the member, an intermediate outwardly-offset substantially cylindrical band portion integrally connected between said front and back wall portions, and an outwardly-oifset substantially cylindrical front nose wall portion connected to said front wall portion.

5. A protector as defined in claim 4 wherein, the threads of said back wall engage the threads of said casing member solely along and immediately adjacent to a pitch cone common to both threads, and the threads on said front wall are in loose alignment with the threads of said casing member with their respective pitch cones offset from one another when the protector is in an assembled position.

6. A protector as defined in claim 4 wherein, the threads of said back wall portions have a pitch line which is common to a pitch line of the threads of said casing member and along which their respective flanks are in contact, and the threads of said front wall portion have a pitch line which is radially-offset from the pitch line of the threads of said casing member about .025 of an inch when the protector is in its mounted position.

References Cited in the file of this patent UNITED STATES PATENTS 1,457,882 Shrum June 5, 1923 1,528,576 Shrum Mar. 3, 1925 1,639,814 Shrum et a1. Aug. 23, 1927 2,156,169 Unke Apr. 25, 1939 2,380,690 Graham July 31, 1945 2,581,690 Moehle et a1. Jan. 8, 1952 2,587,544 .Sneddon Feb. 26, 1952 

